Entolimod is a remedy for radiation exposure, which was developed by Cleveland Biolabs under the support of the United States Department of Defense, and the present disclosure is to produce the “improved entolimod (KMRC011)” as a TLR5 agonist, in which the pre-developed entolimod has been partially modified.
The entolimod was derived from the flagellin protein of Salmonella enterica. It is found that the emtoilimod blocks cell death due to radiation exposure through binding and activation with TLR5 (Toll-like receptor-5). There is a report that in fact, approximately 67% was survived after exposure to monkeys with radiation levels similar to those exposed to firefighters participated at the Chernobyl nuclear accident site, and the entolimod was administrated to the monkeys. On the other hand, the survival rate of monkeys without the substance was approximately 25%.
The entolimod consists of the D0 domain and the D1 domain that directly bind to TLR5 among the flagellin proteins of Salmonella enterica composed of a total of four domains (D0, D1, D2, and D3). The amino terminal thereof includes 34 amino acid residues (MRGSHHHHHHGMASMTGGQQMGRDLYDDDDKDPM (SEQ ID NO: 9)) including the 6-histidine tag and the enterokinase recognition sequence for the purification and the cleavage.
However, the conventional entolimod needs to be removed because it is likely to inhibit binding to TLR5 and induce an immune response by the 34 amino acid residues bound to the amino terminal.
However, since the internal amino acid sequence of the entolimod has a structure vulnerable to protease, there may be a problem that the structure may be destroyed when it is treated with the enterokinase, a kind of protease.
Therefore, a new concept of the entolimod and a method for preparation thereof needs to be developed.
Meanwhile, Korean Patent No. 10-1287905 (issued on Jul. 15, 2013) discloses a method for protecting a patient from radiation using a flagellin, and a method for protecting a patient from one or more treatments inducing apoptosis, which includes administering a composition including a pharmaceutically acceptable amount of the reagent inducing NF-kB to a patient.
Further, Korean Patent Publication No. 10-2012-0104177 (published on Sep. 20, 2012) discloses methods and medicaments for treating cancers and infectious diseases by providing TLR5 for treating cancer and TLR5 agonist such as a flagellin as an agonist.